Contaminant tolerant compressed natural gas injector and method of directing gaseous fuel therethrough

ABSTRACT

An electromagnetically actuable fuel injector for an internal combustion engine is disclosed having an outer housing, a fuel inlet connector positioned in the upper end portion of the outer housing for reception of fuel therein, and an armature having a valve needle attached thereto and positioned adjacent the fuel inlet connector and spaced therefrom by a working gap. The armature defines a generally elongated central opening to receive fuel flow from the fuel inlet connector and has valve needle attached thereto which interacts with a fixed valve having a fixed valve seat associated with the housing to selectively permit fuel to flow through a valve aperture associated with the fixed valve seat. The fuel inlet connector has a fuel outlet end facing a fuel inlet end of the armature and includes a plurality of radially extending raised pads separated by a corresponding plurality of radially extending recessed portions to reduce the contact area between the fuel inlet connector and the armature when the armature is moved upwardly, and to promote fuel flow transversely across the working gap therebetween to establish a first fuel flow path outside of the armature. The first fuel flow path prevents contaminants from accumulating in the working gap. The armature includes at least one first aperture extending through a wall portion thereof for receiving fuel flow from the generally elongated central opening and for directing the fuel flow to a second flow path toward the fixed valve seat. At least one-second aperture extends through a wall portion of the armature and extends at a generally acute angle relative to the longitudinal axis to establish a third fuel flow path toward the fixed valve seat. The size, orientation and numbers of the apertures can be varied to achieve predetermined flow conditions. A method of directing fuel through an injector is also disclosed although the fuel injector and method disclosed utilize gaseous fuels, all types of fuels are contemplated.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application expressly claims the benefit of earlier filingdate and right of priority from the following co-pending patentapplications: U.S. Provisional Application U.S. Serial No. 60/ 086,937,entitled “Contaminant Tolerant Compressed Natural Gas Injector” filedMay 27, 1998; and U.S. Provisional Application U.S. Serial No.60/086,939, entitled “Needle Valve For Low Noise Fuel Injector” filedMay 27, 1998. Both cited provisional patent applications are expresslyincorporated in their entirety by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present application relates to a compressed natural gasinjector, which is tolerant of contamination in the gas.

[0004] 2. Description of the Related Art

[0005] Compressed natural gas (hereinafter sometimes referred to as“CNG”) is becoming a common automotive fuel for commercial fleetvehicles and residential customers. In vehicles, the CNG is delivered tothe engine in precise amounts through gas injectors, hereinafterreferred to as “CNG injectors”. The CNG injector is required to delivera precise amount of fuel per injection pulse and maintain this accuracyover the life of the injector. In order to maintain this level ofperformance for a CNG injector, certain strategies are required to helpreduce the effects of contaminants in the fuel.

[0006] Compressed natural gas is delivered throughout the country in apipeline system and is mainly used for commercial and residentialheating. While the heating systems can tolerate varying levels ofquality and contaminants in the CNG, the tolerance levels in automotivegas injectors are significantly lower.

[0007] These contaminants, which have been acceptable for many years inCNG used for heating, affect the performance of the injectors to varyinglevels and will need to be considered in future CNG injector designs.Some of the contaminants found in CNG are small solid particles, water,and compressor oil. Each of these contaminants needs to be addressed inthe injector design for the performance to be maintained over the lifeof the injector.

[0008] The contaminants can enter the pipeline from several sources.Repair, maintenance and new construction to the pipeline system canintroduce many foreign particles into the fuel. Water, dust, humidityand dirt can be introduced in small quantities with ease during any ofthese operations. Oxides of many of the metal types found in thepipeline can also be introduced into the system. In addition, faultycompressors can introduce vaporized compressor oils, which blow by theseals of the compressor and enter into the gas. Even refueling can forcecontaminants on either of the refueling fittings into the storagecylinder. Many of these contaminants are likely to reach vital fuelsystem components and alter the performance characteristics over thelife of the vehicle.

[0009] In general, fuel injectors require extremely tight tolerances onmany of the internal components to accurately meter the fuel. For CNGinjectors to remain contaminant tolerant, the guide and impact surfacesfor the armature needle assembly require certain specifically uniquecharacteristics. We have invented a CNG fuel injector which represents asignificant improvement over presently known injectors while beingtolerant to contaminants commonly found in compressed natural gas. Wehave also invented a method of directing compressed natural gaseous fuelthrough such injectors in a manner to promote efficient and effectivefiring without misfire.

SUMMARY OF THE INVENTION

[0010] The invention relates to an electromagnetically operable fuelinjector for a gaseous fuel injection system of an internal combustionengine, the injector having a generally longitudinal axis, whichcomprises a ferromagnetic core, a magnetic coil at least partiallysurrounding the ferromagnetic core, an armature magnetically coupled tothe magnetic coil and being movably responsive to the magnetic coil, thearmature actuating a valve closing element which interacts with a fixedvalve seat of a fuel valve and being movable away from the fixed valveseat when the magnetic coil is excited. The armature has a generallyelongated shape and a generally central opening for axial reception andpassage of gaseous fuel from a fuel inlet connector positioned adjacentthereto. The fuel inlet connector and the armature being adapted topermit a first flow path of gaseous fuel between the armature and themagnetic coil and a valve body shell as part of a path leading to thefuel valve. At least one first fuel flow aperture extends through a wallportion of the armature to define a second flow path of gaseous fuel aspart of a path leading to the fuel valve.

[0011] In the preferred embodiment, the armature defines at leastone-second aperture in a wall portion thereof to define a third flowpath of gaseous fuel as part of a path leading to the fuel valve. The atleast one second aperture is oriented at a generally acute angle withrespect to the longitudinal axis. Further, the fuel inlet connector andthe armature are a spaced to define a working gap therebetween and areadapted to permit the first flow path of gaseous fuel within the workinggap. The fuel injector further comprises a valve body positioneddownstream of the armature and having at least one aperture in a wallportion thereof for reception of fuel from at least two of the flowpaths of gaseous fuel from the armature and the fuel inlet connector.

[0012] Further, a valve body shell at least partially surrounds thearmature and the valve body, the valve body shell defining a radialspace with the armature for passage of the first flow path of gaseousfuel between the armature and the valve body shell. The fuel inletconnector is positioned above the armature and is spaced from thearmature by a working gap, the fuel inlet connector defining a throughpassage for directing fuel toward the armature and the fixed valve seat.

[0013] The fuel inlet connector comprises an upper end portion adaptedfor reception of gaseous fuel from a fuel source, and a lower endportion for discharging gaseous fuel, the lower end portion having alower surface which faces an upper surface of the armature, the lowersurface of the fuel inlet connector having a plurality of radiallyextending raised pads defined thereon, the pads having recessed portionstherebetween to permit fuel to flow therethrough and across the workinggap defined between the fuel inlet connector and the armature.

[0014] The armature defines at least one first and at least one secondfuel flow aperture extending through wall portions thereof, the at leastone first and at least one second aperture oriented at an acute anglewith the longitudinal axis, and positioned for directing fueltherethrough toward the fixed valve seat. The lowermost surface of thefuel inlet connector and the armature are adapted to permit gaseous fuelto flow across the working gap and between the armature and the magneticcoil whereby at least three fuel flow paths are permitted. Preferablylowermost end portion of the fuel inlet connector has a generallychamfered configuration along the lowermost outer surface thereof. Thegenerally chamfered portion of the fuel inlet connector preferably has agenerally arcuate cross-section.

[0015] The valve-closing element is a valve needle adapted for selectiveengagement and disengagement with the fixed valve seat and is attachedto the armature by crimped portions of the armature. A fuel filter ispositioned at an upper end portion of the fuel inlet connector forfiltering fuel prior to reception by the fuel inlet connector. The fuelinlet connector includes a lower surface portion having a plurality ofradially extending grooves defining a corresponding plurality ofradially extending raised pads so as to reduce the effective surfacearea of the lower surface portion of the fuel inlet connector facing thearmature to thereby permit the gaseous fuel to flow generallytransversely in the working gap, the transverse fuel flow therebypreventing accumulation of contaminants in the working gap. Thegenerally radially extending pads preferably have a generallytrapezoidal shape, but may be of various shapes, depending upon thecircumstances or results desired. Further, the fuel injector isapplicable to liquid fuel systems such as gasoline, as well as with thepreferred CNG systems.

[0016] The valve closing element is a generally elongated valve needlehaving a spherically shaped end portion and configured and adapted toengage a frust-conically shaped fixed valve seat to close the valve, andmovable therefrom to open the valve to permit fuel to pass therethroughtoward the intake manifold of the internal combination engine. The valveneedle is connected to the lower end portion of the armature by crimpedportions. The resilient device to move the armature to close the valveis a coil spring in engagement at one end with the fuel inlet connectorand at the other end with the armature to bias the armature downwardlytoward the valve seat. The armature includes at least two of the firstapertures extending through wall portions thereof and generallytransverse to the longitudinal axis for receiving fuel from thegenerally axial elongated central opening. The armature mayalternatively define a plurality of the first apertures for receivingfuel from said generally axial elongated central opening. The armaturemay also define a plurality of the second apertures, at least certain ofthe second apertures extending at a generally acute angle to thelongitudinal axis to receive fuel from the generally central opening.

[0017] A method is disclosed for directing gaseous fuel through anelectromagnetically operable fuel injector for a fuel system of aninternal combustion engine, the injector having a generally longitudinalaxis, and including a fuel inlet end portion and a fuel outlet endportion, a fuel inlet connector positioned at the fuel inlet end portionand having a fuel inlet end portion and a fuel outlet end portion, anarmature positioned adjacent the fuel outlet end portion of the fuelinlet connector and having a generally central elongated opening forreception of fuel from said fuel inlet connector, the armature beingspaced from the fuel inlet connector to define a working gap to permitmovement of the armature toward and away from the fuel inlet connectorto selectively open and close a fuel valve to permit gaseous fuel topass therethrough to an air intake manifold. The method comprises,directing the gaseous fuel to pass axially through the fuel inletconnector, directing the gaseous fuel to pass from the fuel inletconnector to the generally elongated central opening of the armature inan axial direction toward the fuel valve, directing at least a portionof the fuel flow from the fuel inlet connector to the armature to flowgenerally transversely across the working gap, and diverting at least aportion of the flow of gaseous fuel passing through the armature to flowin a direction away from the axial direction. The step of directing thegaseous fuel passing through the armature to flow in a direction awayfrom the axial direction is preferably accomplished by directing thegaseous fuel through at least one first aperture provided in a wallportion of the armature. Preferably the at least one first aperture inthe wall portion of the armature extends generally transverse to theaxial direction. A lower end portion of the fuel inlet connectorpreferably faces an upper end portion of the armature and is configuredto permit the gaseous fuel to flow from the fuel inlet connector to bedirected transversely across the working gap. Preferably at least aportion of the gaseous fuel flowing in the armature is permitted to passthrough at least one second aperture in a lower wall portion thereof,the at least one second aperture extending at an acute angle to thelongitudinal axis, whereby at least three separate fuel flow paths areestablished. The injector preferably comprises a magnetic coil systemand said armature is magnetically coupled to the magnetic coil system tocause the armature to move toward and away from the fuel inletconnector. At least one of the fuel flow paths is located between thearmature and the magnetic coil of the magnetic coil system, as well asbetween the armature and a valve body shell at least partiallysurrounding the armature. The at least one first and second apertures inthe armature are preferably from about 1 to about 2.0 mm in diameter.Further, predetermined numbers of the first and second apertures areprovided and the diameters thereof are predetermined to establish apredetermined number of fuel flow paths and volumetric flow ratesthereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Preferred embodiments of the invention are described hereinbelowwith reference to the drawings wherein:

[0019]FIG. 1 is an elevational view, partially in cross-section, of apreferred embodiment of a compressed natural gas injector constructedaccording to the invention;

[0020]FIG. 2 is an enlarged elevational cross-sectional view of thelower portion of the injector of FIG. 1, showing the improved armatureand needle which forms part of the invention;

[0021]FIG. 3 is a partial elevational cross-sectional view of the lowerend portion of the fuel inlet connector of the injector shown in FIG. 1;

[0022]FIG. 4 is a plan view of the bottom surface of the preferred fuelinlet connector shown in FIG. 1;

[0023]FIG. 5 is an elevational cross-sectional view of a preferredembodiment of the armature shown in FIG. 1 and illustrating the improvedfuel flow paths resulting therefrom;

[0024]FIG. 6 is an elevational cross-sectional view of the upper portionof a preferred embodiment of the valve body shown in FIG. 1;

[0025]FIG. 7 is a partial elevational cross-sectional view of the lowerend portion of an alternative embodiment of the fuel inlet connectorshown in FIG. 3;

[0026]FIG. 8 is a plan view of the bottom surface of the fuel inletconnector shown in FIG. 7;

[0027]FIG. 9 is an elevational cross-sectional view of an alternativeembodiment of the armature shown in FIG. 5;

[0028]FIG. 10 is an elevational cross-sectional view of the upperportion of an alternative embodiment of the valve body shown in FIG. 6;

[0029]FIG. 11 is an enlarged elevational view of the armature shown inFIG. 5 and a cross-sectional view of the valve body shown in FIG. 6,incorporating an improved valve needle a fuel columnating jet flowdevice;

[0030]FIG. 12 is an enlarged elevational view, partially incross-section, of the armature shown in FIG. 5, and the improved valveneedle shown in FIG. 11;

[0031]FIG. 13 is an enlarged cross-sectional view illustrating thesealing tip portion of the valve needle as seated on the fixed valveseat as shown in FIGS. 1 and 11, illustrating the preferred dimensionalrelationship between the needle tip, the fixed valve seat and the lowerneedle guide; and

[0032]FIG. 14 is a view taken along lines 14-14 of FIG. 11, illustratinga preferred valve needle lower guide having arcuately shaped fuelpassage openings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Referring initially to FIG. 1 there is shown a CNG injector 10which is constructed according to the present invention. Injectors ofthe type contemplated herein are described in commonly assigned U.S.Pat. No. 5,494,224, the disclosure of which is incorporated by referenceherein.

[0034] The injector 10 includes housing 12 containing armature 14 towhich valve needle 16 is attached by crimping as will be described laterin conjunction with FIG. 12. Fuel inlet connector 18 includes centralfuel flow opening 13 and CNG filter 20 at the upper end portion ofopening 19 as shown. The fuel inlet connector 18 also includes adjustingtube 22 connected thereto at 24 by a known crimping procedure. Housing12 includes inner non-magnetic shell 26 which surrounds the inletconnector 18 and armature 14 having central fuel flow opening 11 asshown. Armature 14 and inlet connector 18 define with housing 12, anenclosure for coil 28 which is selectively energized to move armature 14and needle 16 upwardly to open the valve aperture 41, and selectivelydeenergized to permit armature 14 and needle 16 to return to the “closedvalve” position as shown, under the force of coil spring 30. Fuel flowinto the injector begins at filter 20 and passes through fuel inletconnector 18, to armature 14, and ultimately to valve aperture 41 ofvalve seat 40 into the intake manifold of the engine (not shown).

[0035] Referring further to FIG. 1 in conjunction with FIG. 2, valvebody shell 32, which is made of a ferromagnetic material and which formspart of a magnetic circuit, surrounds valve body 34 and has at the upperend, upper guide 36 as shown. Space 36 a between upper guide 36 andarmature 14 is about 0.010 to about 0.015 mm on the diameter, andpermits guiding movement of armature 14. Lower O-rings 38 providesealing between the injector 10 and the engine intake manifold (notshown) and upper O-rings 40 provide sealing between the injector 10 andthe fuel rail (also not shown). Valve body 34 defines central fuel flowopening 35.

[0036] In FIG. 2, valve body shell 32 is attached to valve body 34,preferably by weld 32 a, and at the upper end by weld 26 a, tonon-magnetic shell 26. Non-magnetic shell 26 is in turn welded to fuelinlet connector at 26 b. Thus, fuel flowing from fuel inlet connector 18across working gap 15 must flow through the clearance space 14 a betweenarmature 14 and valve body shell 32 which is also provided to permitupward and downward movement of armature 14. The space 14 a isapproximately 0.10 to 0.30 mm on the diameter.

[0037] Referring again to FIGS. 1 and 2, valve seat 40 contains a valveorifice 41 and a funnel shaped needle rest 42 having a frusto-conicalcross-sectional shape. The valve seat 40 is maintained in position byback-up washer 44 and sealed against fuel leakage with valve body 34 byO-ring 46. Overmold 48 of suitable plastic material such as nylonsupports terminal 50 which extends into coil 28 and is connected viaconnection 51 to provide selective energization of the coil to open thevalve by raising the armature 14 and valve needle 16 against the forceof spring 30. Coil 28 is surrounded by dielectric plastic material 53 asshown in the FIGS.

[0038] In injectors of this type, the interface space 15 (or working gap15) between the inlet connector and the armature is extremely small,i.e. in the order of about 0.3 mm (millimeters), and functionsrelatively satisfactorily with conventional fuels which are relativelyfree of contaminants such as water, solids, oil, or the like,particularly after passing through a suitable fuel filter. Accordingly,when the two surfaces surrounding space 15 are in such intimate contactthat the atmosphere between them is actually displaced in relativelysignificant amounts, atmospheric pressures acting on the two membersactually force the two surfaces together. Any liquid contaminant presentat the armature/inlet connector interface would allow for the atmosphereto be displaced, thereby adversely affecting the full and free operationof the armature/needle combination.

[0039] When known injectors, which functioned at relatively acceptablelevels with relatively clean conventional fuels, were utilized with CNG,impurities such as oil or water at the inlet connector/armatureinterface produced a force of about 16.5 Newtons holding the armature tothe inlet connector. In comparison, the force provided by spring 30 isin the order of about 3 Newtons, thus fully explaining the erraticclosing of the armature/valve needle when the fuel utilized with knowninjectors is CNG. In particular, the 16.5 Newton force holding the inletconnector and armature together is due to the fact that the fueloperating pressure within the injector is about 8 bar (i.e. 8atmospheres) and this force of about 16.5 Newtons acts across the lowersurface area of the inlet connector 18, which is about 21 squaremillimeters (i.e. mm²). Thus a relatively minor slick of oil or otherimpurity within space 15 of a known injector will cause the inletconnector and the armature to become temporarily attached to each other,particularly due to the 8 bar pressure acting on the remaining surfacesof the inlet connector and armature. As noted, the tendency for thearmature to become attached to the inlet connector results in erraticvalve closing.

[0040] Significant features of the present invention are provided interalia, to eliminate the aforementioned erratic valve closing and improvethe operation of the injector. In FIG. 3, the lower end portion of inletconnector 18 is configured as shown by the arcuately chamfered end 52.This configuration provides a beneficial effect in that it directs andorients the magnetic field across the working gap 15 in a manner whichoptimizes the useful magnetic force created for moving the armaturethrough the working gap. This feature is disclosed in commonly assigned,commonly filed (Attorney Docket No. 99P7609US) application entitled“Compressed Natural Gas Fuel Injector Having Magnetic Pole Face FluxDirector, ” the disclosure of which is incorporated herein by reference.Additional features are disclosed in commonly assigned, commonly filed(Attorney Docket No. 99P7610US) copending application entitled“Compressed Natural Gas Injector having Gaseous Dampening for ArmatureNeedle Assembly during Opening,” the disclosure of which is incorporatedherein by reference.

[0041] In addition, as shown in FIG. 4, radial slots in the form ofrecessed surfaces 18 a are provided in the lowermost surface of inletconnector 18 to reduce the effective contact surface area between thearmature and the inlet connector by about one third of the totalcross-sectional area which was utilized in prior art conventionalinjectors. This configuration provides six coined pads 18 b of about0.05 mm in height, thus creating six corresponding rectangular shapedradial slots 18 a to provide fuel flow paths. By reducing, the effectivesurface area of the lowermost face of the inlet connector 18 as shown,the tendency to develop an attractive force between the inlet connector18 and the armature 14 is significantly reduced to about one-third ofits original value, and the ability to tolerate fuel contaminants at theinterface without producing an attractive force therebetween is alsosignificantly increased. As noted, preferably, the rectangular radialslots 18 a are of a shallow depth, i.e. about 0.05 mm, (i.e.,millimeters) in order to provide the benefit of reducing the inletconnector/armature interface surface area while still providing arelatively unobtrusive location for collection of solid contaminantswhich are ultimately removed by the flow of gaseous CNG.

[0042] As noted, the provision of recessed surfaces 14 a in thelowermost surface of inlet connector 18 creates raised pads 18 b on thesurface, which pads improve the tolerance of the injector to fuelcontaminants in several ways. The recessed surfaces 18 a may be made byany suitable process, but are preferably coined. The first effect is toreduce the contact area of the inlet connector at the armatureinterface, thereby significantly reducing any attractive force generatedtherebetween by liquid contaminants such as oil or water. Furthermore,as noted, the radial pads 18 b provide hidden areas between the padswhere contaminants can collect without affecting the operative workinggap 15 until being drawn away by the fuel flow. The working gap forgasoline is about 0.08 mm to about 0.14 mm, and about 0.3 mm forcompressed natural gas. In addition, as noted, the provision of the sixrectangular recessed portions in the form of slots 18 a and six raisedpads 18 b, each having a generally trapezoidal shape, on the inletconnector, provide a unique fuel flow path past the inletconnector/armature interface in a manner which causes the gaseous fuelto pass transversely through the working gap 15 as shown at 56 in FIG. 5and allow for the control of the fuel flow around and through thearmature by controlling the pressure losses.

[0043] Also, by controlling the sizes of the recessed surfaces 18 a andraised pads 18 b, and the various apertures 58, 60, 66 in the armatureand the valve body as will be described—as well as the numbers andcombinations of such openings—the fuel flow can be controlled over atleast three flow paths and pressure losses can also be controlled. Forexample, a small pressure differential across the armature while fullyopen, assists spring 30 during breakaway upon closing and providesdampening on opening impact. The additional fuel flow path also reducesthe possibility of contaminants collecting above upper guide 36 as shownin FIG. 2. In summary, numerous combinations of apertures and sizesthereof—as well as slots and pads on the fuel inlet connector—can bemade to direct the gaseous fuel flow in any desired manner which is bestfor optimum fuel burning and engine application.

[0044] Referring now to FIGS. 5 and 6 in conjunction with FIGS. 1-3,there is illustrated still another significant improvement, whichrenders the fuel injector assembly more fully capable of operation withCNG. In prior art injectors which were used with relatively contaminantfree fuels the fuel would pass through the filter down through the inletconnector into the armature and out an opening positioned relativelyclose to the lowest portion of the armature which was locatedsubstantially immediately above the valve aperture. In the presentstructure there is provided a relatively diagonally oriented aperture 58shown in FIG. 5, which directs the CNG flow therethrough and downwardlytoward valve aperture 41 for entry into the intake manifold of theinternal combustion engine.

[0045] As shown in FIG. 5, aperture 58 forms a generally acute anglewith longitudinal axis A-A of the fuel injector 10. In addition, thearmature of the present invention provides at least one side opening 60which is generally transverse to the longitudinal axis A-A, to permitfuel flowing downwardly through the center of the armature to bedirected sidewardly out of the armature and thereafter downwardly towardthe valve aperture 41 shown in FIG. 1. In the embodiment shown in FIG.1, aperture 60 is generally horizontal, but may be oriented at an acuteangle to the longitudinal axis if desired. Aperture 58 is not shown inthe cross-sectional view of FIG. 1. The fuel flowing through aperture 60is indicated by the flow lines 62 and the fuel flowing through aperture58 is indicated schematically by flow lines 64. Optionally severaladditional horizontal apertures 60 may be provided in the armature atdifferent radial locations thereabout, or alternatively as shown, oneaperture 60 may be provided, depending upon the fuel flow pattern soughtin each particular instance. It can be seen that the fuel flow from thefuel inlet connector 18 is divided into three paths, a first pathexpanding across working gap 15, a second path through aperture(s) 60,and a third path through aperture(s) 58. The first path extends betweenthe armature 14 and the magnetic coil 28 and is ultimately joined by thesecond flow path passing through aperture(s) 60.

[0046] It can also be readily appreciated that the diameters of eachaperture 58, 60 can be varied to direct the fuel flow in anypredetermined desired direction. For example, by reducing the size ofapertures 58,60 fuel will be encouraged to flow with increased volumecross the working gap 15. Alternatively, increasing the diameter ofapertures 58, 60 will attract greater volume of fuel through thoseapertures and thereby reduce the fuel flow across the working gap. Ithas also been found that the diameters of the apertures 58, 60 and thenumbers and locations of such apertures affect the dampingcharacteristics of the valve needle 16, both upon opening and uponclosing. Accordingly, the diameter of fuel flow apertures 58, 60 and thenumbers, locations, and orientations of such apertures will depend uponthe desired volumetric flow characteristics and desired flow patterns ineach instance; however diameters within the range of 1-2 mm have beenfound to be preferable.

[0047] Referring now to FIG. 6, a valve body 34 is also provided withcentral fuel flow opening 35 and several diagonally oriented fuel pathapertures 66 which are intended to receive the CNG fuel flowing from thefirst and second flow paths from the working gap 15 and aperture(s) 60along the sides of the armature 14 and to redirect the fuel downwardlytoward the valve aperture 41 such that when the needle 16 is lifted, thefuel is permitted to enter aperture 41 and thereafter directed into theintake manifold of the engine, neither of which are shown in thedrawings. Fuel flowing along the third flow path through aperture(s) 58lead directly toward aperture 41. It has been found that the uniqueprovisions of the apertures 58 and 60—as well as rectangular radialslots 18 a on the inlet connector lowermost face—create a fuel flowpattern which induces the CNG to flow in the manner shown by the fuelflow lines at 56, 62 and 64 in FIG. 5 and such fuel flow lines actuallycreate ideal pressure conditions to avoid causing the armature to beattracted to the inlet connector. Thus the attractive forces between thearmature and inlet connector are minimized by the several factorsmentioned, namely the elimination of the tendency of the oil andcontaminates to accumulate in the space 15 located between the armatureand the inlet connector, the reduction of the effective inletconnector/armature interface area by provision of radial pads on theface of the inlet connector, and the provision of the unique CNG flowpattern which creates a force free environment between the inletconnector and the armature.

[0048] As indicated, alternatively, apertures 60 may be provided inseveral locations about the circumference of the armature, and apertures58 may be provided in several locations thereabout. Also their angularorientations may be varied. However, it has been found that a singleaperture on each side, as shown is sufficient to produce the desiredflow path and the force free environment. Also, as noted, it should benoted that the diameter of each aperture can be altered in order toprovide control of the fuel pressures and flow patterns in the areassurrounding the inlet connector, the armature, and the valve body, so asto provide a predetermined fuel flow pattern throughout the injector asmay be desired. This feature is more fully disclosed in theaforementioned commonly assigned, commonly filed (Attorney Docket No.99P7610US) copending application entitled Compressed Natural GasInjector Having Gaseous Damping for Armature Needle Assembly DuringOpening.

[0049] It should also be noted that the presence of the diagonallyoriented fuel flow apertures 66 in valve body 34 eliminates the problemsof prior art injectors wherein debris and contaminants would accumulatein the area of the upper valve guide 36, causing abrasive action andintermittent guidance between the upper guide 36 and the armature 14.Thus, the provision of the diagonally oriented apertures 66 in valvebody 34 encourage the flow of CNG past the area surrounding the upperguide 36 and eliminate any accumulation tendencies for contaminants inthe area of upper guide 36.

[0050] Referring now to FIGS. 7 and 8 in conjunction with FIGS. 1-3,there is illustrated an alternative embodiment of the lower end portionof the inlet connector 18 and the lowermost face of the inlet connector18. In this embodiment inlet connector 18 includes arcuately chamferedsurface 52 on the lowermost end of inlet connector 18 as in the previousembodiment. In FIG. 8, the lowermost surface of inlet connector 18defines a surface area 67 between concentric circles 70 and 72 as shown.While the inlet connector/armature contact area is not reduced as in theembodiment of FIGS. 3 and 4, the operation of the injector is improvedover the prior art injectors. Accordingly, the alternative embodiment asshown in FIGS. 7 and 8 will provide substantially improved operation forthe injector as shown as compared with prior art injectors when utilizedwith CNG.

[0051] Referring to FIGS. 9 and 10 in conjunction with FIGS. 1-3, thereis shown still another alternative embodiment of the armatureconfiguration for use with CNG the armature in valve assemblyconfiguration for use with CNG. In FIG. 9 the armature assembly 73contains a diagonally shaped relatively large fuel flow opening 74 atthe lower portion thereof, while the horizontal fuel opening 60 in thearmature of FIG. 5 has been eliminated. In addition, in the valve body76 shown in FIG. 10, central flow opening 75 is provided, and thediagonal fuel flow openings 66 of the embodiment of FIG. 6 have beeneliminated and the fuel flow as depicted at 71 in FIG. 10 will thereforebe directed out of diagonal aperture 74 and into valve assembly 76 asshown in FIGS. 9 and 10.

[0052] The CNG fuel path created by the combination of the inletconnector and armature shown in FIGS. 7-10 represents a significantimprovement over prior art structures. However, the armature and valveassembly shown in FIGS. 3-6 are preferred. It should be noted that thestructures disclosed in FIGS. 7-10 produce satisfactory and improvedoperation and may alternatively be considered to be a preferredembodiment, depending upon the particular environment in which they areutilized. For example, in certain injectors dimensional and clearanceconsiderations may very well create a flow pattern which will mandate apreference to utilizing the embodiments of FIGS. 7-10 as opposed to thepreviously disclosed embodiments of FIGS. 3-6.

[0053] Referring now to FIGS. 11 and 12 in conjunction with FIGS. 1-3,there is disclosed an enlarged elevational view of the improved armatureof the present invention, the improved valve body of the presentinvention, and the improved valve needle which has been incorporatedinto the disclosed structure. In particular, the armature 14 containsside fuel flow aperture(s) 60 and the valve body 34 contains thediagonal CNG fuel flow path openings 66. The armature 14 has attachedthereto by a known crimping procedure at 78, an improved valve needle16.

[0054] The improved valve components of the present fuel injector aredisclosed in FIGS. 1, 11 and 12 incorporating the improved needle 16.During operation or the fuel injector, the armature 14 moves upwardlyand downwardly due to the energization and deenergization of coil 30 soas to produce alternating opening and closing contact between valveneedle 16 and valve seat 40. As the needle is raised to permit the CNGfuel flow through the aperture 41 the flow passes the tip portion 17 ofthe needle and enters aperture 41 in its flow path toward the intakemanifold of the engine.

[0055] In conventional liquid fuel injection systems having aconventional elongated needle having a continuous cylindrically shapedouter surface, the needle presents several problems and disadvantages.When applied to CNG systems, the problems inherent with conventionalneedles are intensified, particularly due to the changes in the gaseousenvironment as compared to the liquid environment. Accordingly, thepresent invention incorporates a novel valve needle which improves theoperation characteristics of fuel injection systems, including liquidfuel and gaseous fuel types.

[0056] It has been known that when conventional valve needles engage avalve seat of a fuel injector the force of impact with conventionalneedles can generate sounds within the engine compartment which aregenerally perceived as either a mechanical problem or otherwise harsh orobjectional noises emanating from the engine. This force of impact—whichis equal to the valve component mass multiplied by the acceleration—isgenerally caused by the relatively substantial velocity of the needleduring its movement toward the “valve closed” position in engagementwith the valve seat. Accordingly, the needle 16 which forms part of thepresent injection system, has been structured to eliminate disadvantagesof prior art needles. Although this needle has been found to improveperformance with gaseous fuel injection systems as in the presentinvention, it has also been found to improve the performance of liquidfuel injection systems.

[0057] With the improved needle shown in FIG. 11, it has been found thatit is desirable to provide a generous radius sealing portion 19 at thevalve end of the needle in order to maximize the contact area betweenthe valve needle 16 and the valve seat 40. For example, the greater theradius at the tip of the needle, the better the sealing between theneedle and the valve seat 40. Preferably, the radius of the sphericalsealing section 19 of needle 16 is in the order of about 1.75millimeters (i.e., mm), or about 1.5 times the radius of thecorresponding sealing surfaces in the prior art structures. However,needles which are generally known for conventional injectors of the typedisclosed herein generally have a continuous outer cylindricalconfiguration from the upper end to the lower end, thus requiring aneedle of relatively large needle cross-sectional area in order toprovide a relatively large sealing surface. The needle 16 of the presentinvention as shown in FIG. 11 is a relatively low mass needle asdisclosed, yet includes a relatively large spherical sealing surface.

[0058] In particular, the mass of the needle has been substantiallyreduced by reducing the cross-sectional dimension of the shaft 21 of theneedle and retaining a tip portion 17 which is greater incross-sectional dimension then the shaft of the needle as shown. Thisconfiguration effectively reduces the mass of the needle while retainingthe relatively large sealing diameter of spherical surface 17 b of thetip portion 17 so as to provide a relatively generous radius at thetip-or free end-portion of the needle for engagement with the valve seat40. It has been found that the relatively reduced mass of the needle andthe relatively large radius of the tip portion 17 makes it possible toprovide a generous spherical sealing surface 19 for the needle for agiven amount of CNG flow. The generous radius also results in a shortertraveling distance for the needle 16 thereby reducing the impactvelocity of the needle relative to the valve seat. It has beendetermined that for a predetermined flow rate, this configurationresults in a significant reduction of the noise produced by the impactbetween the needle 16 and the valve seat 40. Furthermore, theattenuation of the apparent noise is a result of reducing the amplitude(via reduction of lift of the needle 16) and lowering the frequency (viathe greater impact radius of tip portion 17) of the noise into a lessobjectionable region of the sound spectrum as perceived by the humanear.

[0059] In addition to reduced noise, the improved needle of the presentinvention provides a larger guide surface relative to the mean needlediameter, thereby improving the wear resistance of the guiding surfaceof lower guide 80 shown in FIG. 11. This improved wear resistance of theguide surface is due to the reduced loading compared to that of aconventional base valve guide diameter which was used with needles ofthe prior art. For example, a typical prior art needle will have asubstantially continuous cylindrically shaped shaft which terminates ata radiussed end portion wherein the shaft diameter may be twice as muchas the diameter of the shaft of the improved needle shown in FIG. 11. Onthe other hand, the tip portion 17 of the needle shown in FIG. 11 can beconfigured to have a diameter up to approximately 50% greater than thediameter of the shaft 19 of needle 16 thereby having a greater diameterthan would otherwise be present in a prior art needle and thereby makingprovision for a lower guide 80 having a guide surface which is greaterin diameter and surface area than would otherwise be utilized with priorart needles. This improves the wear resistance of the guide surface dueto the reduced loading as compared to that of the conventional basevalve guide diameter. Significant features of the needle disclosedherein are also disclosed in commonly assigned, commonly filed (AttorneyDocket No. 98P7678US01) application entitled “Compressed Needle GasInjector Having Improved Low Noise Valve Needle,” the disclosure ofwhich is incorporated herein by reference.

[0060] In FIG. 13, the preferred dimensional relationship between theimproved needle 16 and the funnel shaped valve needle rest 42 is shownin greater detail. As noted with respect to FIG. 1, needle 16 includes acentral shaft portion and a cylindrical needle tip portion 17 having aspherical lower surface 17 b which engages the frusto-conically shapedsurface 42 of needle rest 40. The needle is guided by upper guide 36guiding armature 16 as shown in FIG. 1, and lower guide 80 guidingneedle tip portion 17 as shown in FIGS. 13 and 14. Upper guide 36 isinherently required to provide a space 36 a between the guiding surfaceand the armature 14, to permit the upward and downward motion of thearmature and needle. Thus the armature 14 and needle 16 may have thetendency to shift to the left or right at the upper guide 36 withinspace 36 a which is about 0.10 to about 0.15 mm on the diameter,preferably about 0.13 mm.

[0061] Referring now to FIG. 13, it has been found to be advantageous tolocate the center of generation 17 c of spherical sealing surface 17 bof needle tip portion 17 at the center of the lowermost surface of lowerguide 80 as shown, in order to assure precise seating and sealing ofneedle 16 on frusto-conical needle rest 42. In particular, by suchpositioning of the center 17 c of spherical sealing surface 17 b of tipportion 17, the lower guide 80 tends to constrain sideward movement ofthe needle tip portion 17 due to movement of armature 16 within upperguide 36, and effectively becomes a nodal point about which needle tipportion 17 is capable of rotating over 360 degrees of motion. Thus anysideward movement of the needle which occurs at the level of armature 14and upper guide 36, will cause the needle to pivot about the centerpoint 17 c and promote self seating of sealing surface 17 b on needlerest 40. This self-seating feature also applies in the event that anymisalignment or manufacturing tolerance buildup occurs in therelationship between upper guide 36 and needle 16.

[0062] As noted, the present needle 16 is advantageous for use withinjectors, which utilize CNG as is contemplated herein, as well as withinjectors which utilize liquid fuels, such as gasoline. In particular,in injectors utilizing liquid fuels, the motion of the valve needle isalso damped by displacement of fluid across the extended valve seal faceand the valve seat which further reduces the impact force anduncontrolled secondary injections upon closure caused by the valveneedle when it rebounds away from the valve seat. In such injectors usedwith liquid fuels, valve rebound produces quantities of low velocityfuel droplets after the needle started to close. Valve rebound dampeningminimizes low volume/velocity fuel transfer to the aperture 41. Thus,the dampening of the needle rebound improves the operation of theinjector by minimizing low volume/low velocity fuel transfer to theorifice and the surrounding area which tends to extendedly suspend fueldroplets via surface tension when liquid fuels are used. Valve rebounddampening has also been found to be beneficial in the present injectorwhich is contemplated for use with gaseous CNG.

[0063] Referring now to FIG. 14, in conjunction with FIG. 11, lowervalve needle guide 80 is illustrated in the form of a disc shaped memberhaving arcuately shaped fuel passage apertures 82 which direct thegaseous CNG in a more efficient and effective manner as compared toprior art valve guides which utilized a plurality of circular openingsformed along a circular pattern. The apertures 82 are larger than theprior art circular apertures and are more effective in directing andcontrolling the fuel flow in an efficient manner by forming the flowpattern into several arcuate flow paths.

[0064] Referring now to FIG. 12, the improved armature 14 is illustratedwith valve needle 16 crimped thereto at 78 by known crimping procedures;however, valve body 34 has been eliminated for purposes of clarity ofillustration in the enlarged view of armature 14 and needle 16. In FIG.12, the illustration of needle 16 clearly shows the main shaft portion21 and the enlarged tip portion 17 with enlarged valve spherical sealingsurface 17 b which conveniently engages and disengages seat area 42 ofvalve needle rest 40 as described in conjunction with FIG. 13.

[0065] Referring again to FIG. 11, the injector 10 incorporates a fuelcolumnating jet device 84 which includes a shallow funnel shaped section86 connected to a generally tubular shaped columnating section 88.Gaseous fuel passing through valve aperture 41 is then allowed to passthrough funnel shaped section 86, and then to be columnated into asteady gaseous stream in columnating section 88 The fuel columnatingdevice 88 enhances mixture quality, reduces fuel delivery time andenables single or multiple discharge orientation for improved gaseousflow targeting. A narrow gaseous flow discharge angle can entrain thesurrounding working fluid (mostly air) and can impart useful turbulentenergies to directed air/fuel mixtures flowing through a port, intakevalve and/or into a combustion chamber to reduce in-cylinder air/fuelmixture gradients. This feature has proven to significantly reduceengine misfire and to improve exhaust emissions, and is also disclosedin commonly assigned, commonly filed (Attorney Docket No. 99P7611US)application entitled “Gaseous Injector With Columnated Jet Orifice andor Flow Directing Device, ” the disclosure of which is incorporatedherein by reference.

[0066] It has been found that the injector of the present inventionprovides improved operation for the reasons stated hereinabove byimproving the flow pattern of the CNG as described, improving thecontrol over the valve needle operation and movements thereof, andimproving the sealing characteristics of the needle type valveincorporated as part of the injector. As noted hereinabove, noisecharacteristics and needle dampening both upon opening and upon closing,have been significantly improved by the present invention and with theresult that the injector as shown and described is significantlyimproved for use with compressed natural gas (CNG) fuels.

[0067] Although the present invention is particularly intended for usewith CNG fuels, it is self evident that the use of any liquid or gaseousfuels are contemplated, particular those fuels which are relatively highin contamination, since the tolerance of the contaminants has been fullyaddressed by the disclosed structures.

[0068] Although the invention has been described in detail withreference to the illustrated preferred embodiments, variations andmodifications may be provided within the scope and spirit of theinvention as described and as defined by the following claims.

1. An electromagnetically operable fuel injector for a gaseous fuelinjection system of an internal combustion engine, said injector havinga generally longitudinal axis, which comprises: a) a ferromagnetic core;b) a magnetic coil at least partially surrounding the ferromagneticcore; c) an armature magnetically coupled to said magnetic coil andbeing movably responsive to said magnetic coil, said armature actuatinga valve closing element which interacts with a fixed valve seat of afuel valve and being movable away from said fixed valve seat when saidmagnetic coil is excited, said armature having a generally elongatedshape and a generally central opening for axial reception and passage ofgaseous fuel from a fuel inlet connector positioned adjacent thereto,said fuel inlet connector and said armature being adapted to permit afirst flow path of gaseous fuel between said armature and said magneticcoil as part of a path leading to said fuel valve; and d) at least onefirst fuel flow aperture extending through a wall portion of saidarmature to define a second flow path of gaseous fuel as part of a pathleading to said fuel valve.
 2. The electromagnetically operable fuelinjector according to Claim 1, wherein said armature defines at leastone second aperture in a wall portion thereof to define a third flowpath of gaseous fuel as part of a path leading to said fuel valve. 3.The electromagnetically operable fuel injector according to Claim 2,wherein said at least one-second aperture is oriented at a generallyacute angle with respect to the longitudinal axis.
 4. Theelectromagnetically operable fuel injector according to Claim 3, whereinsaid fuel inlet connector and said armature are spaced to define aworking gap therebetween and are adapted to permit said first flow pathof gaseous fuel within said working gap.
 5. The electromagneticallyoperable fuel injector according to Claim 3, further comprising a valvebody positioned downstream of said armature and having at least oneaperture in a wall portion thereof for reception of fuel from at leasttwo of said flow paths of gaseous fuel from said armature and said fuelinlet connector.
 6. The electromagnetically operable fuel injectoraccording to Claim 5, further comprising a valve body shell at leastpartially surrounding said armature and said valve body, said valve bodyshell defining a radial space with said armature for passage of saidfirst flow path of gaseous fuel between said armature and said valvebody shell.
 7. The electromagnetically operable fuel injector accordingto Claim 6, wherein said fuel inlet connector is positioned above saidarmature and is spaced from said armature by a working gap, said fuelinlet connector defining a through passage for directing fuel towardsaid armature and said fixed valve seat.
 8. The electromagneticallyoperable fuel injector according to Claim 7, wherein said fuel inletconnector comprises an upper end portion adapted for reception ofgaseous fuel from a fuel source, and a lower end portion for discharginggaseous fuel, said lower end portion having a lower surface which facesan upper surface of said armature, said lower surface of said fuel inletconnector having a plurality of radially extending raised pads definedthereon, said pads having recessed portions therebetween to permit fuelto flow therethrough and across said working gap defined between saidfuel inlet connector and said armature.
 9. An electromagneticallyoperable fuel injector for a compressed natural gas fuel injectionsystem of an internal combustion engine, said injector having agenerally longitudinal axis, which comprises: a) a ferromagnetic core;b) a magnetic coil at least partially surrounding said ferromagneticcore; c) an armature coupled to said magnetic coil and movablyresponsive to said magnetic coil, said armature having a first upper endface and a lower end portion; d) a valve closing element connected tosaid lower end portion of said armature and interactive with a fixedvalve seat to selectively permit fuel to pass through said valve seat assaid valve closing element is moved to a valve open position by saidarmature; e) a fuel inlet connector extending in a generallylongitudinal direction above said armature and defining a path for fuelto enter said inlet connector and to be directed toward said armature,said fuel inlet connector having a lowermost end portion having alowermost surface spaced above said armature to define a working gapthrough which said armature is movable; and f) said armature having afuel reception portion for receiving fuel directed from said fuel inletconnector, said armature further defining a generally axial fuel passageand at least a first fuel flow aperture extending through a wall portionthereof for directing fuel from said fuel inlet connector through saidgenerally axial fuel passage and into said aperture toward said fixedvalve seat for entry into an air intake manifold for the engine, saidfuel flow aperture being oriented generally transverse to saidlongitudinal axis.
 10. The electromagnetically operable fuel injectoraccording to Claim 9, wherein said armature further defines at least asecond fuel flow aperture extending through a lower portion thereof andoriented at an acute angle with said longitudinal axis, and positionedfor directing fuel therethrough toward said fixed valve seat.
 11. Theelectromagnetically operable fuel injector according to Claim 10,wherein said lowermost surface of said fuel inlet connector and saidarmature are adapted to permit gaseous fuel to flow across said workinggap and between said armature and said magnetic coil whereby at leastthree fuel flow paths are permitted.
 12. The electromagneticallyoperable fuel injector according to Claim 11, wherein said lowermost endportion of said fuel inlet connector has a generally chamferedconfiguration along the lowermost outer surface thereof.
 13. Theelectromagnetically operable fuel injector according to Claim 12,wherein said generally chamfered portion of said fuel inlet connectorhas a generally arcuate cross-section.
 14. The electromagneticallyoperable fuel injector according to Claim 13, wherein said valve closingelement is a valve needle adapted for selective engagement anddisengagement with said fixed valve seat.
 15. The electromagneticallyoperable fuel injector according to Claim 14, wherein said valve needleis attached to said armature by crimped portions of said armature. 16.The electromagnetically operable fuel injector according to Claim 15,wherein a fuel filter is positioned at an upper end portion of said fuelinlet connector for filtering fuel prior to reception by said fuel inletconnector.
 17. The electromagnetically operable valve according to Claim16, wherein said fuel inlet connector includes a lower surface portionhaving a plurality of radially extending grooves defining acorresponding plurality of radially extending raised pads so as toreduce the effective surface area of said lower surface portion of saidfuel inlet connector facing said armature to thereby permit the gaseousfuel to flow generally transversely in said working gap, said transversefuel flow thereby preventing accumulation of contaminants in saidworking gap.
 18. The electromagnetically operable fuel injectoraccording to Claim 17, wherein said generally radially extending padshave a generally trapezoidal shape.
 19. An electromagnetically operablefuel injector for a gaseous fuel injection system of an internalcombustion engine, said injector having a generally longitudinal axis,which comprises: a) a ferromagnetic core; b) a magnetic coil at leastpartially surrounding the ferromagnetic core; c) an armaturemagnetically coupled to said magnetic coil and being movably responsiveto said magnetic coil, said armature actuating a valve closing elementwhich interacts with a fixed valve seat of a fuel valve and beingmovable away from said fixed valve seat when said magnetic coil isexcited, said armature having a generally elongated shape and agenerally central opening for axial reception and passage of gaseousfuel from a fuel inlet connector positioned adjacent thereto, said fuelinlet connector having a lower surface portion having a continuousannular surface having a circular shape; and d) at least one first fuelflow aperture extending through a wall portion of said armature forreception of gaseous fuel flowing from said inlet connector and fordirecting the gaseous fuel to a valve body at least partiallysurrounding said armature, said valve body having a generally elongatedcentral opening for reception of substantially all of the gaseous fuelfrom said armature.
 20. The electromagnetically operable fuel valveaccording to Claim 19, wherein said at least one first fuel flowaperture extending through a wall portion of said armature is orientedat a generally acute angle with respect to said generally longitudinalaxis.
 21. An electromagnetically operable fuel injector for an internalcombustion engine, said injector defining a generally longitudinal axis,which comprises: a) an outer housing; b) a fuel inlet connectorpositioned in the upper end portion of said outer housing, said fuelinlet connector having an uppermost end portion for reception of fueltherein and a lowermost end portion for discharge of fuel therefrom: c)an armature positioned below said fuel inlet connector and defining agenerally axial elongated central opening to receive fuel flow from saidfuel inlet connector, said armature having an uppermost end portionpositioned below said lowermost end portion of said fuel inlet connectorto define a working gap, and a lowermost end portion having a valveclosing element positioned thereon for interaction with a fixed valvehaving a fixed valve seat associated with said housing to selectivelypermit fuel to flow through a valve aperture associated with said fixedvalve seat when said armature is selectively moved upwardly toward saidfuel inlet connector; d) said fuel inlet connector having a lowermostend portion having a lowermost surface which faces said uppermost endportion of said armature, said lowermost end portion of said fuel inletconnector having a plurality of radially extending grooves separated bya corresponding plurality of radially extending raised pads to reducethe effective contact surface area between said inlet connector and saidarmature and to permit fuel to flow from said fuel inlet connectoracross said working gap; e) a magnetic coil system for moving saidarmature and said valve closing element away from said fixed valve seatand toward said fuel inlet connector when said magnetic coil system isenergized so as to permit fuel to flow through said fixed valve seat; f)a resilient device to bias said armature and said valve closing elementto move toward said fixed valve seat when said magnetic coil system isdeenergized; g) at least one first aperture extending through a wallportion of said armature for receiving fuel flow from said fuel inletconnector and directing said fuel flow from said generally elongatedcentral opening of said armature toward said fixed valve seat, said atleast one aperture being generally transverse to the longitudinal axis;and h) at least one second aperture extending through a wall portion ofsaid armature for receiving fuel flow from said fuel inlet connector anddirecting said fuel flow toward said fixed valve seat, said secondaperture being oriented at a generally acute angle relative to thelongitudinal axis for directing fuel from said generally central openingoutwardly of said armature and downwardly toward said fixed valve seat.22. The electromagnetically operable fuel injector according to Claim21, wherein said valve closing element is a generally elongated valveneedle having a spherically shaped end portion and configured andadapted to engage a frusto-conically shaped fixed valve seat to closesaid valve, and movable therefrom to open said valve to permit fuel topass therethrough toward the intake manifold of the internal combinationengine.
 23. The electromagnetically operable fuel injector according toClaim 22, wherein said valve needle is connected to the lower endportion of said armature by crimped portions.
 24. Theelectromagnetically operable fuel injector according to Claim 23,wherein said resilient device is a coil spring in engagement at one endwith said fuel inlet connector and at the other end with said armatureto bias said armature downwardly toward said valve seat.
 25. Theelectromagnetically operable fuel injector according to Claim 24,wherein said armature includes at least two of said first aperturesextending through wall portions thereof and generally transverse to thelongitudinal axis for receiving fuel from said generally axial elongatedcentral opening.
 26. The electromagnetically operable fuel injectoraccording to Claim 25, wherein said armature defines a plurality of saidfirst apertures for receiving fuel from said generally axial elongatedcentral opening.
 27. The electromagnetically operable fuel injectoraccording to Claim 26, wherein said armature defines at least aplurality of said second apertures, each said second apertures extendingat a generally acute angle to the longitudinal axis to receive fuel fromsaid generally central opening.
 28. A method of directing gaseous fuelthrough air electromagnetically operable fuel injector for a fuel systemof an internal combustion engine, said injector having a generallylongitudinal axis, and including a fuel inlet end portion and a fueloutlet end portion, a fuel inlet connector positioned at said fuel inletend portion and having a fuel inlet end portion and a fuel outlet endportion, an armature positioned adjacent said fuel outlet end portion ofsaid fuel inlet connector and having a generally central elongatedopening for reception of fuel from said fuel inlet connector, saidarmature being spaced from said fuel inlet connector to define a workinggap to permit movement of said armature toward and away from said fuelinlet connector to selectively open and close a fuel valve to permitgaseous fuel to pass therethrough to an air intake manifold, comprising:a) directing the gaseous fuel to pass axially through said fuel inletconnector; b) directing the gaseous fuel to pass from said fuel inletconnector to said generally elongated central opening of said armaturein an axial direction toward said fuel valve; c) directing at least aportion of the fuel flow from said fuel inlet connector to said armatureto flow generally transversely across said working gap; and d) divertingat least a portion of the flow of gaseous fuel passing through saidarmature to flow in a direction away from said axial direction.
 29. Themethod according to Claim 28, wherein said step of directing the gaseousfuel passing through said armature to flow in a direction away from theaxial direction is accomplished by directing the gaseous fuel through atleast one first aperture provided in a wall portion of said armature.30. The method according to Claim 29, wherein said aperture in said wallportion of said armature extends generally transverse to said axialdirection.
 31. The method according to Claim 30, wherein a lower endportion of said fuel inlet connector facing an upper end portion of saidarmature is configured to permit said gaseous fuel to flow from saidfuel inlet connector to be directed transversely across said workinggap.
 32. The method according to Claim 31, wherein at least a portion ofthe gaseous fuel flowing in said armature is permitted to pass throughat least one second aperture in a lower wall portion thereof; said atleast one second aperture extending at an acute angle to saidlongitudinal axis, whereby at least three separate fuel flow paths areestablished.
 33. The method according to Claim 32, wherein said injectorcomprises a magnetic coil system having a magnetic coil, and saidarmature is magnetically coupled to said magnetic coil system to causesaid armature to move toward and away from said fuel inlet connector, atleast one of said fuel flow paths being located between said armatureand said magnetic coil.
 34. A method of directing compressed natural gasthrough an electromagnetically operable fuel injector for a fuel systemof an internal combustion engine, said injector having a generallylongitudinal axis, and including a fuel inlet end portion and a fueloutlet end portion, a fuel inlet connector positioned at said fuel inletend portion, and an armature positioned adjacent said fuel inletconnector and said fuel outlet end portion of said injector, saidarmature being spaced from said fuel inlet connector to define a workinggap to permit movement of said armature toward and away from said fuelinlet connector, said armature having a generally axial fuel passageopening and having attached thereto a valve needle having an end portionadapted to selectively disengage and engage a fuel valve to open andclose said valve to permit gaseous fuel to pass therethrough,comprising: a) directing the gaseous fuel through said fuel inletconnector; b) directing the gaseous fuel to pass from said fuel inletconnector to said fuel passage opening of said armature in an axialdirection toward said fuel valve; c) directing at least a portion of theflow of gaseous fuel passing through said armature to flow through atleast one first aperture in a wall portion of said armature, saidaperture extending in a direction generally transverse to said axialdirection; d) directing at least a portion of the flow of gaseous fuelpassing through said armature to flow in a direction at an acute angleto said axial direction through at least one second aperture in a lowerwall portion of said armature; and e) directing at least a portion ofthe flow of gaseous fuel passing from said fuel inlet connector to saidarmature to flow generally transverse to said axial direction acrosssaid working gap between said fuel inlet connector and said armature soas to establish at least three separate fuel flow paths between saidfuel inlet portion and said fuel outlet portion of said injector. 35.The method according to Claim 34, wherein said fuel inlet connectorincludes a plurality of adjacent raised pads on a lowermost end portionthereof, said raised pads being respectively spaced by adjacent recessedportions to permit the flow of gaseous fuel through said working gapwhen said armature moves toward said fuel inlet connector to therebyopen said fuel valve.
 36. The method according to Claim 35, wherein saidat least one first and second apertures in said armature are from about1 to about 2.0 mm in diameter.
 37. The method according to Claim 36,wherein predetermined numbers of said first and second apertures areprovided and the diameters thereof are predetermined to establish apredetermined number of fuel flow paths and volumetric flow ratesthereof.
 38. A method of directing fuel through an electromagneticallyoperable fuel injector for a fuel system of an internal combustionengine, said injector having a generally longitudinal axis, andincluding a fuel inlet end portion and a fuel outlet end portion, a fuelinlet connector positioned at said fuel inlet end portion, and anarmature positioned adjacent said fuel inlet connector and said fueloutlet end portion of said injector, said armature being spaced fromsaid fuel inlet connector to define a working gap to permit movement ofsaid armature toward and away from said fuel inlet connector, saidarmature having a generally axial fuel passage opening for reception offuel from said fuel inlet connector, and having attached thereto a valveneedle having an end portion adapted to selectively disengage and engagea fuel valve to open and close said valve to permit fuel to passtherethrough, comprising: a) directing the fuel through said fuel inletconnector; b) directing the fuel to pass from said fuel inlet connectorto said fuel passage opening of said armature in an axial directiontoward said fuel valve; c) directing at least a portion of the flow offuel passing from said fuel inlet connector to said armature to flowgenerally transverse to said axial direction across said working gapbetween said fuel inlet connector and said armature so as to establishat least one separate fuel flow path outside of said armature. d)directing at least a portion of the flow of fuel passing through saidarmature to flow at least along a second flow path through at least onefirst aperture in a wall portion of said armature, said apertureextending in a direction generally transverse to said axial direction;and e) directing at least a portion of the flow of fuel passing throughsaid armature to flow at least along a third flow path in a direction atan acute angle to said axial direction through at least one secondaperture in a lower wall portion of said armature.